From the Richmond Sentinel, 3/30/1863, p. 2, c. 3

Attempted Escape.
– Capt. A. Webster, one of Pierpont’s officers, confined in the Government
Thunder prison of this city under sentence of death, nearly succeeded in making
his escape on Friday night last. He was in the hospital, guarded, when by some
means he slipped his irons off, leaped from his bed and made for a window. The
guard snapped his musket, but it failed to explode, and Webster having succeeded
in getting upon a projecting roof jumped down to the ground. Here he was fired
upon without effect, but having sprained an ankle in his jump, his locomotion
was slow, and he was soon recaptured.